Use cursor keys to move highlight through the process list. While cursor keys in use, pause the updates. Use the ESC key to abort selection.
When enter/return key is hit, use a ncurses window to show information about the process, as with Activity Monitor:

Use cursor keys to move highlight through the process list. While cursor keys in use, pause the updates. Use the ESC key to abort selection.
When enter/return key is hit, use a ncurses window to show information about the process, as with Activity Monitor: